Biofortification of food crops: a novel strategy for reducing micronutrient malnutrition

Abstract

More than two billion people across the world are iron (Fe) and zinc (Zn) deficient, the majority of them are rural poor living in developing countries. Poor people cannot afford diversified diets, nutrient supplements and fortified foods. Thus, biofortification appears to be a good means of enriching micronutrients to food crops and it can be done through conventional breeding, transgenic or agronomic approach. Landraces and wild relatives having high mineral contents are used in the breeding programme to develop new varieties with high yield and elevated mineral characteristics. In conventional breeding, parent lines with high mineral levels are crossed and back-crossed over several generations to produce plants that have enhanced level of minerals. Transgenic approach has made it possible to transfer candidate gene from the same or a different species or organism to the intended crops that low in minerals. Internationally the ‘HarvestPlus’ programme has taken initiative to address micronutrient malnutrition of rural poor in developing countries through development of staple food crop varieties (rice, wheat, maize, cassava, pearl millet, beans and sweet potato) that rich in Fe, Zn and Vitamin A (β-carotene). The whole amount of minerals present in plant foods is not bioavailable to humans due to presence of antinutritional compounds (e.g. phytate) that interferes with the absorption of nutrients. Agronomic biofortification provides temporary micronutrient increase through fertilizer application. This approach could be complementary to breeding strategy for achieving greater success of breeding efforts for micronutrient enrichment of food crops. This paper presents a comprehensive review of the progress of biofortification research, indicating a sustainable strategy to enhance the micronutrient concentration in staple foods and thereby reducing micronutrient malnutrition.